Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 4b8a9674 authored by Catalin Marinas's avatar Catalin Marinas
Browse files

kmemleak: Add more cond_resched() calls in the scanning thread 



Following recent fix to no longer reschedule in the scan_block()
function, the system may become unresponsive with !PREEMPT. This patch
re-adds the cond_resched() call to scan_block() but conditioned by the
allow_resched parameter.

Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
Cc: Ingo Molnar <mingo@elte.hu>
parent bf2a76b3

mm/kmemleak.c

+11 −8
Original line number Diff line number Diff line
@@ -807,7 +807,7 @@ static int scan_should_stop(void) 
 * found to the gray list.

 */

static void scan_block(void *_start, void *_end,

		       struct kmemleak_object *scanned)

		       struct kmemleak_object *scanned, int allow_resched)

{

	unsigned long *ptr;

	unsigned long *start = PTR_ALIGN(_start, BYTES_PER_POINTER);
@@ -818,6 +818,8 @@ static void scan_block(void *_start, void *_end, 
		unsigned long pointer = *ptr;

		struct kmemleak_object *object;



		if (allow_resched)

			cond_resched();

		if (scan_should_stop())

			break;
@@ -881,12 +883,12 @@ static void scan_object(struct kmemleak_object *object) 
		goto out;

	if (hlist_empty(&object->area_list))

		scan_block((void *)object->pointer,

			   (void *)(object->pointer + object->size), object);

			   (void *)(object->pointer + object->size), object, 0);

	else

		hlist_for_each_entry(area, elem, &object->area_list, node)

			scan_block((void *)(object->pointer + area->offset),

				   (void *)(object->pointer + area->offset

					    + area->length), object);

					    + area->length), object, 0);

out:

	spin_unlock_irqrestore(&object->lock, flags);

}
@@ -931,14 +933,14 @@ static void kmemleak_scan(void) 
	rcu_read_unlock();



	/* data/bss scanning */

	scan_block(_sdata, _edata, NULL);

	scan_block(__bss_start, __bss_stop, NULL);

	scan_block(_sdata, _edata, NULL, 1);

	scan_block(__bss_start, __bss_stop, NULL, 1);



#ifdef CONFIG_SMP

	/* per-cpu sections scanning */

	for_each_possible_cpu(i)

		scan_block(__per_cpu_start + per_cpu_offset(i),

			   __per_cpu_end + per_cpu_offset(i), NULL);

			   __per_cpu_end + per_cpu_offset(i), NULL, 1);

#endif



	/*
@@ -960,7 +962,7 @@ static void kmemleak_scan(void) 
			/* only scan if page is in use */

			if (page_count(page) == 0)

				continue;

			scan_block(page, page + 1, NULL);

			scan_block(page, page + 1, NULL, 1);

		}

	}
@@ -972,7 +974,8 @@ static void kmemleak_scan(void) 
		read_lock(&tasklist_lock);

		for_each_process(task)

			scan_block(task_stack_page(task),

				   task_stack_page(task) + THREAD_SIZE, NULL);

				   task_stack_page(task) + THREAD_SIZE,

				   NULL, 0);

		read_unlock(&tasklist_lock);

	}